Okay. So you know when you have to find outliers you multiply the IQR by 1.5, But why is it 1.5? Does any one know. If you need more details let me know. Please leave your resources. Thanks.
2006-09-13 14:13:06 · 2 answers · asked by Softball_Super_Star17 3 in Education & Reference ➔ Homework Help
There isn't any certain reason as to why it's 1.5. The lined had to be drawn somewhere, and everyone agrees on 1.5.
2006-09-13 14:20:04 · answer #1 · answered by frisbee72001 3 · 0⤊ 0⤋
The choice of 1.5 IQR is arbitrary. Just like we may use Confidence levels of 90%, 95%, 99%, 99.5% etc.
By definition, IQR covers 50% of the items. When we extend the range by 1.5 IQR bothways, the coverage is 99.3% if the distribution is normal. Can you use any value other than 1.5 IQR? Sure, you can so long as you have a good reason for it (except that do not do it during examinations).
2006-09-13 21:40:48 · answer #2 · answered by Jacob Gan 2 · 0⤊ 0⤋